Telephonic protector against electromagnetic effects.



No. 890,850. 7 I PATENTED JUNE 16, 1908. O. DUO.

TBLBPHONIO PROTECTOR AGAINST ELECTROMAGNETIC EFFECTS.

APPLICATION rILnn NOV. 30. 1900.

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No. 890,850. v PATENTED JUNE 16, 1908.-

0. D176. TELBPHONIG PROTECTOR AGAINST, ELEOTROMAGNETIG EFFECTS.

APPLICATION FILED NOV. 30, 190B.

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UNITED STATES PATENT OFFICE.

GELIO DUO, OF BUENOS AYRES, ARGENTINA.

Specification of Letters Patent.

Patented June 16, 1908.

Application filed November 30, 1906. Serial No. 345,732.

To all whom it may concern:

Be it known that I, OELro Duo, a subject of the King of Italy, residing at 343B Mitre street, Buenos Ayres, Argentina, have invented certain new and useful Improvements in Telephonic Protectors Against Electromagnetic Effects, of which the following is a specification.

The object of this invention is to provide means rendering it possible to utilize upon the same wire and simultaneously if desired, a telephone and a telegraph apparatus, while protecting the telephone against interruptions due to telegraphic work or against any other current or magnetic effects.

It is well known that the alternating currents upon assing over a coil which surrounds a so t iron nucleus, produce in said coil a variable magnetic flow, proportional at all times to the intensity of the current.

The present invention, therefore, consists of means which utilizes the difference men tioned, and which protects the telephone against the electro-magnetic effects caused by the telegraphic currents, or an alternating current of low frequency, which generally cause noises rendering telephone conversation difficult.

In the accom anying drawings, I have shown a bobbin for accomplishing the result sought and a method of winding and utilizing such bobbin.

Figure 1 is a diagrammatic view of a wellknown form of soft iron core or'nucleus provided with two windings; Fi 2 is an enlarged diagrammatic view, il ustrating the relation of the several layers of the wires according to this invention; Fig. 3 is a crosssectional view of a bobbin wound according to my new method; Fig. 4. is a diagrammatic view, illustrating the back and forth windings or layers upon such bobbin; Fig. 5 illustrates a modification of Fi 2, and Fig. 6 illustrates (diagrammatically) a telephone station employing the apparatus of Fig. 5.

For an understanding of the present invention, let it be supposed that the core or nucleus, N-N, of soft iron is provided (Fig. 1) with a surrounding insulating coil, A A, forming a closed circuit. In addition, there is an independent conductor, D D, also insulated, coiled upon the nucleus and parallel with the conductor first mentioned. If now an electro-magnetic current reaches the described simple bobbin over winding Dand D, such current will magnetize the nucleus or core, N N, inducing an extra current over the winding A A, and will pursue its way without being hindered by the bobbin. If, however, a current of high frequency having electrostatic effect and low intensity, such as a telephonic current, comes over winding D D, both parallel wires, A A and D D, separated by an insulator, will act somewhat like the armatures of a condenser, (considering that the first and second wires represent said armatures) and the small energy available from the current will be entirely used in charging such condenser and be absorbed.

The separate conductors referred to may each be provided with a plurality of windings or layers upon the single nucleus or core, and one form thereof is illustrated (both diagrammatically and in section) in Figs. 2 and 3. Fig. 4 shows the back and forth relation of the several windings or layers.

Around the soft iron core or nucleus, N N, the operator first winds the coil D, and around such coil he then winds a coil A of a different conductor; around the coil A, the operator then winds a third separate coil B. The coils D, A and B are all wound in the same direction, and when the coil B is completed such and in the direction opposite thereto, to complete a coil B. Around such coil B, the operator then winds the continuation of wire A, or a wire connected therewith, and continues such winding (in a direction opposite to A) until a coil A is completed. Around the last-named coil, the operator winds a coil D, using for such purpose the conductor of coil D or a wire connected therewith, and winding in the direction opposite to D; the winding D is continued until it reaches the point D (Fig. 2). The two free extremities leading from coils A and B may now be fastened together or connected with a single conductor, and the two free extremities from the coils A and B may be united with a telephone, such as T.

An electro-magnetic variation at D, will i induce a flow of null energy on the endless wire, A, A, B, B, A (formed as before described) because by electro-mtgnetic induction at D, D, there will be produced at A and B, currents which are opposed to the variations of current at D D, so that currents being induced in the same direction at A and at B, the resulting current in the circuit will be null, this being also the case with the effect of D D upon the circuit A, B, B, A,' On the conductor is then wound around the coil B,

charge at D, D) will induce on the neighboring wire A, a positive charge, and said wire A, would induce a negative charge on B D D will induce at A a positive charge, and the latter will induce a negative charge at B i so that one pole of the telephone will'have'a positive charge by the wire A, A and the other a negative charge by the'wire B, B; when oscillations of these electro-static charges are produced at D, D these oscillations will re-occur in an inverted manner at A, A and will be again inverted at B, B and the telephone will vibrate through these oscillations of extremely small intensity.

The telephone T will show the effect of only the small electrostatic vibrations, and

, known devices,

consequently when speaking through the wire D, D D the telephone T will receive the conversation, but will not be sensible to the interruptions of low frequency, such as telegraphic interruptions that pass through the same wire owing to its electro-magnetic nature.

If it is desired to interpose in the circuit A, A B B, two telephones instead of one, it is sufficient to place the second telephone T on the N extremities of the wires A B as indicated in Fig. 5.

This device, as herein described, is therefore used for the protection of the telephone, against any electro-magnetic effect and will render great services both in telegraphy and telephony, especially by adding one of the consisting in interposing between the apparatus and the line, a self-induction, and in derivation with the ground, a condenser, and in adding to this apparatus 40 some of the numerous phonic calling apparatus, in order to facilitate the service the wire of the microphone and caller may be conveniently coiled upon the bobbin, so that a call from a telephonic station will be heard at the following station (see Fig. 6).

What I claim is: V

1. In a telephone protector, a bobbin composed of a nucleus of metal, an insulated conductor wound around said nucleus, a second insulated conductor wound around that firstnamed, a third insulated conductor wound around that second-named and also wound in the oppositedirection around its first winding, a fifth winding around that last-men tioned and in continuation of that secondnamed; a sixth winding around the fifth and in continuation of the first-named winding, and a telephone in circuit with the conductor of the second and third windings.

2. In a telephone protector, a bobbin composed of a nucleus of metal, an insulated conductor wound around said nucleus, a second insulated conductor wound around that firstnamed, a third insulated conductor wound around that second-named and also wound in the opposite direction around its first winding, a fifth winding around that last-mentioned and in continuation of that secondnamed, and a sixth winding around the fifth and in continuation of the first-named Winding, the conductor of the second and third windings being electrically connected at their extremities.

In testimony whereof I affix my signature in presence of two witnesses.

OELIO DUO.

Witnesses 7 JUAN A. OARvAL, E. B. WEIDEMER. 

